The exploitation of new catalysts and new organic transformations in an environmentally benign manner has became crucially important in recent years for the construction of new and useful organic structures from versatile starting materials. In this context, organocatalysis has recently emerged as a powerful synthetic paradigm in order to fill a gap between metal- and enzyme-catalysis, thereby providing practical alternatives or complementary technologies to the more traditional transition metal-catalyzed systems. Organocatalysis is an attractive method to synthesize complex organic molecules: it is operationally simple, has low associated toxicity and organocatalysts are simple to handle and store. In addition, a wide variety of organocata...